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3.
Neuromolecular Med ; 25(3): 426-440, 2023 09.
Article in English | MEDLINE | ID: mdl-37460789

ABSTRACT

Exposure to cadmium, a heavy metal distributed in the environment is a cause of concern due to associated health effects in population around the world. Continuing with the leads demonstrating alterations in brain cholinergic signalling in cadmium induced cognitive deficits by us; the study is focussed to understand involvement of N-Methyl-D-aspartate receptor (NMDA-R) and its postsynaptic signalling and Nrf2-ARE pathways in hippocampus. Also, the protective potential of quercetin, a polyphenolic bioflavonoid, was assessed in cadmium induced alterations. Cadmium treatment (5 mg/kg, body weight, p.o., 28 days) decreased mRNA expression and protein levels of NMDA receptor subunits (NR1, NR2A) in rat hippocampus, compared to controls. Cadmium treated rats also exhibited decrease in levels of NMDA-R associated downstream signalling proteins (CaMKIIα, PSD-95, TrkB, BDNF, PI3K, AKT, Erk1/2, GSK3ß, and CREB) and increase in levels of SynGap in hippocampus. Further, decrease in protein levels of Nrf2 and HO1 associated with increase in levels of Keap1 exhibits alterations in Nrf2/ARE signalling in hippocampus of cadmium treated rats. Degeneration of pyramidal neurons in hippocampus was also evident on cadmium treatment. Simultaneous treatment with quercetin (25 mg/kg body weight p.o., 28 days) was found to attenuate cadmium induced changes in hippocampus. The results provide novel evidence that cadmium exposure may disrupt integrity of NMDA receptors and its downstream signaling targets by affecting the Nrf2/ARE signaling pathway in hippocampus and these could contribute in cognitive deficits. It is further interesting that quercetin has the potential to protect cadmium induced changes by modulating Nrf2/ARE signaling which was effective to control NMDA-R and PI3K/AKT cell signaling pathways.


Subject(s)
Proto-Oncogene Proteins c-akt , Quercetin , Rats , Animals , Quercetin/pharmacology , Quercetin/therapeutic use , Proto-Oncogene Proteins c-akt/metabolism , N-Methylaspartate/metabolism , Cadmium/toxicity , Cadmium/metabolism , Phosphatidylinositol 3-Kinases/metabolism , Kelch-Like ECH-Associated Protein 1/metabolism , NF-E2-Related Factor 2/genetics , NF-E2-Related Factor 2/metabolism , Signal Transduction , Receptors, N-Methyl-D-Aspartate/genetics , Hippocampus , Cognition
4.
Neurotoxicology ; 96: 101-117, 2023 05.
Article in English | MEDLINE | ID: mdl-37060950

ABSTRACT

The risk to develop neurobehavioural abnormalities in humans on exposure to lambda-cyhalothrin (LCT) - a type II synthetic pyrethroid has enhanced significantly due to its extensive uses in agriculture, homes, veterinary practices and public health programs. Earlier, we found that the brain dopaminergic system is vulnerable to LCT and affects motor functions in rats. In continuation to this, the present study is focused to unravel the role of neuroinflammation in LCT-induced neurotoxicity in substantia nigra and corpus striatum in rats. Increase in the mRNA expression of proinflammatory cytokines (TNF- α, IL-1ß, IL-6) and iNOS whereas decrease in anti-inflammatory cytokine (IL-10) was distinct both in substantia nigra and corpus striatum of rats treated with LCT (0.5, 1.0, 3.0 mg/kg body weight, p.o, for 45 days) as compared to control rats. Further, LCT-treated rats exhibited increased levels of glial fibrillary acidic protein (GFAP) and ionized calcium-binding adapter molecule 1 (Iba-1), the glial marker proteins both in substantia nigra and corpus striatum as compared to controls. Exposure of rats to LCT also caused alterations in the levels of heat shock protein 60 (HSP60) and mRNA expression of toll-like receptors (TLR2 and TLR4) in the substantia nigra and corpus striatum. An increase in the phosphorylation of key proteins involved in NF-kß (P65, Iκß, IKKα, IKKß) and JAK/STAT (STAT1, STAT3) signaling and alteration in the protein levels of JAK1 and JAK2 was prominent in LCT-treated rats. Histological studies revealed damage of dopaminergic neurons and reactive gliosis as evidenced by the presence of darkly stained pyknotic neurons and decrease in Nissl substance and an increase in infiltration of immune cells both in substantia nigra and corpus striatum of LCT-treated rats. Presence of reactive microglia and astrocytes in LCT-treated rats was also distinct in ultrastructural studies. The results exhibit that LCT may damage dopaminergic neurons in the substantia nigra and corpus striatum by inducing inflammation as a result of stimulation of neuroglial cells involving activation of NF-κß and JAK/STAT signaling.


Subject(s)
Pyrethrins , Humans , Rats , Animals , Pyrethrins/metabolism , Substantia Nigra/metabolism , Dopaminergic Neurons/metabolism , Cytokines/genetics , Cytokines/metabolism , Tumor Necrosis Factor-alpha/metabolism , Inflammation/metabolism , RNA, Messenger/metabolism , Corpus Striatum/metabolism
5.
J Chem Neuroanat ; 118: 102035, 2021 12.
Article in English | MEDLINE | ID: mdl-34597812

ABSTRACT

Early-life viral infections critically influence the brain development and have been variously reported to cause neuropsychiatric diseases such as Schizophrenia, Parkinson's diseases, demyelinating diseases, etc. To investigate the alterations in the dopaminergic system, myelination and associated behavioral impairments following neonatal viral infection, the viral immune activation model was created by an intraperitoneal injection of Poly I:C (5 mg/kg bw/ip) to neonatal rat pups on PND-7. The DA-D2 receptor binding was assessed in corpus striatum by using 3H-Spiperone at 3, 6 and 12 weeks of age. MOG immunolabelling was performed to check myelination stature and myelin integrity, while corpus callosum calibre was assessed by Luxol fast blue staining. Relative behavioral tasks i.e., motor activity, motor coordination and neuromuscular strength were assessed by open field, rotarod and grip strength meter respectively at 3, 6 and 12 weeks of age. Following Poly I:C exposure, a significant decrease in DA-D2 receptor binding, reduction in corpus callosum calibre and MOG immunolabelling indicating demyelination and a significant decrease in locomotor activity, neuromuscular strength and motor coordination signify motor deficits and hypokinetic influence of early life viral infection. Thus, the findings suggest that early life poly I:C exposure may cause demyelination and motor deficits by decreasing DA-D2 receptor binding affinity.


Subject(s)
Behavior, Animal/drug effects , Myelin Sheath/drug effects , Neostriatum/drug effects , Neostriatum/metabolism , Poly I-C/toxicity , Receptors, Dopamine D2/drug effects , Animals , Animals, Newborn , Corpus Callosum/cytology , Corpus Callosum/drug effects , Male , Motor Activity/drug effects , Muscle Strength/drug effects , Psychomotor Performance/drug effects , Rats , Rats, Wistar , Spiperone/pharmacology
6.
Mol Neurobiol ; 57(10): 4117-4133, 2020 Oct.
Article in English | MEDLINE | ID: mdl-32676988

ABSTRACT

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder with no cure. The reports showed the role of nearby astrocytes around the motor neurons as one among the causes of the disease. However, the exact mechanistic insights are not explored so far. Thus, in the present investigations, we employed the induced pluripotent stem cells (iPSCs) of Cu/Zn-SOD1L39R linked ALS patient to convert them into the motor neurons (MNs) and astrocytes. We report that the higher expression of stress granule (SG) marker protein G3BP1, and its co-localization with the mutated Cu/Zn-SOD1L39R protein in patient's MNs and astrocytes are linked with AIF1-mediated upregulation of caspase 3/7 and hyper activated autophagy. We also observe the astrocyte-mediated non-cell autonomous neurotoxicity on MNs in ALS. The secretome of the patient's iPSC-derived astrocytes exerts significant oxidative stress in MNs. The findings suggest the hyperactive status of autophagy in MNs, as witnessed by the co-distribution of LAMP1, P62 and LC3 I/II with the autolysosomes. Conversely, the secretome of normal astrocytes has shown neuroprotection in patient's iPSC-derived MNs. The whole-cell patch-clamp assay confirms our findings at a physiological functional level in MNs. Perhaps for the first time, we are reporting that the MN degeneration in ALS triggered by the hyper-activation of autophagy and induced apoptosis in both cell-autonomous and non-cell autonomous conditions.


Subject(s)
Amyotrophic Lateral Sclerosis/pathology , Astrocytes/metabolism , Autophagy , Motor Neurons/pathology , Superoxide Dismutase-1/genetics , Amyotrophic Lateral Sclerosis/physiopathology , Apoptosis/genetics , Autophagy/genetics , Cell Differentiation , Electrophysiological Phenomena , Gene Expression Regulation , Humans , Induced Pluripotent Stem Cells/metabolism , Lysosomes/metabolism , Matrix Metalloproteinases/metabolism , Models, Biological , Neural Stem Cells/metabolism , Oxidative Stress , Reactive Oxygen Species/metabolism
7.
Sci Rep ; 10(1): 6909, 2020 Apr 20.
Article in English | MEDLINE | ID: mdl-32312997

ABSTRACT

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

10.
Ann Neurosci ; 26(3-4): 35-41, 2019 Jul.
Article in English | MEDLINE | ID: mdl-32843831

ABSTRACT

BACKGROUND: Exposure to adverse environmental conditions such as toxic chemicals, viral infections, and even stress during pregnancy or early life may disrupt the development of normal brain and its functioning leading to incidence of neurodevelopmental disorders at later stages of life. Recently, we reported that poly (I:C) exposure altered synaptic plasticity protein level and impaired memory through activation of microglia cells. PURPOSE: As epigenetic modifications are involved in memory formation, we have studied methylation of DNA and acetylation of histone at promoters of synaptic plasticity genes in the brain of rats exposed to poly (I:C) during early life. METHODS: One dose of poly (I:C) (5 mg/kg bw) was intraperitoneally injected to rat pups on postnatal seventh day. A set of pups exposed to vehicle was included as control. In order to assess methylation of DNA and acetylation of histone at synaptic plasticity gene promoter, we performed qPCR after methylated DNA immunoprecipitation and chromatin immunoprecipitation. RESULTS: Poly (I:C) exposure reduced the level of 5-methylcytosine (5mC) at synaptic plasticity gene (bdnf, arc, and egr1) promoters in the frontal cortex (FC) and hippocampus of 3-week rats, although increased it later in both regions of 12-week rats as compared to respective controls. On contrary, poly (I:C) exposure enhanced acetylation of histone H3K9 (H3K9Ac) at promoters of these genes in both regions of 3-week rats but decreased in 12-week rats. CONCLUSION: Poly (I:C) exposure altered 5mC and H3K9Ac at synaptic plasticity gene promoters resulting in memory impairment of rats at later life.

11.
Neurobiol Learn Mem ; 155: 379-389, 2018 11.
Article in English | MEDLINE | ID: mdl-30195050

ABSTRACT

Viral infection during early stage of life influences brain development and results in several neurodevelopmental disorders such as schizophrenia, autism and behavioral abnormalities. However, the mechanism through which infection causes long-term behavioral defects is not well known. To elucidate this, we have used synthetic polyinosinic-polycytidylic acid [poly (I:C)] which acts as a dsRNA molecule and interacts with toll-like receptor-3 (TLR-3) of microglia cells to evoke the immune system, thus mimicking the viral infection. Rat pups of postnatal day (PND) 7 were infused with a single dose of poly (I:C) (5 mg/kg BW) and vehicle alone to controls. When these pups grew to 3, 6 and 12 weeks, their spatial and fear conditioning memory were impaired as assessed by Morris water maze and passive avoidance test, respectively. We checked the immune activation by staining of TNF-α in the hippocampus and observed that poly (I:C) exposure elevated the number of TNF-α positive cells immediately after 12 h of infusion in one week rat and it persisted up to postnatal age of 3 and 12 weeks. Moreover, poly (I:C) significantly decreased the binding of 3H-QNB to the cholinergic receptors in the frontal cortex and hippocampus of 3 and 6 weeks rats as compared to control but did not change significantly in 12 weeks rats. RT-PCR and immunoblotting results showed that poly (I:C) exposure upregulated the expression of memory associated genes (BDNF, Arc, EGR1) at mRNA and protein level in frontal cortex and hippocampus of 3 weeks rats as compared to control. However, long-time persistence of poly (I:C) effects significantly decreased the expression of these genes in both brain regions of 12 weeks rats. Taken together, it is evident that early life exposure to poly (I:C) has a long-term effect and impairs learning and memory, probably through TNF-α mediated neuroinflammation and alteration in the expression of memory associated genes in frontal cortex and hippocampus of rats.


Subject(s)
Brain/growth & development , Brain/immunology , Memory/physiology , Neuronal Plasticity/genetics , Neuronal Plasticity/immunology , Spatial Learning/physiology , Animals , Brain/drug effects , Conditioning, Classical/drug effects , Conditioning, Classical/physiology , Female , Frontal Lobe/drug effects , Frontal Lobe/immunology , Gene Expression , Hippocampus/drug effects , Hippocampus/immunology , Male , Memory/drug effects , Neuronal Plasticity/drug effects , Poly I-C/administration & dosage , Rats, Wistar , Receptors, Muscarinic/metabolism , Spatial Learning/drug effects , Tumor Necrosis Factor-alpha/metabolism
12.
Mol Neurobiol ; 54(6): 4705-4715, 2017 08.
Article in English | MEDLINE | ID: mdl-27447805

ABSTRACT

Cholinergic system has an important role in memory and learning. Abnormal cognitive and behavioral changes have been reported in Japanese encephalitis (JE), but their basis has not been comprehensively evaluated. In this study, we report memory and learning and its association with acetylcholinesterase (AChE) activity, JE virus titer, and with histopathological observations in a rat model of JE. Wistar rats were intracerebrally inoculated on 12th day with 3 × 106 pfu/ml of JE virus. Memory and learning were assessed by the active and passive avoidance tests on 10, 33, and 48 days post inoculation (dpi). After 10, 33, and 48 dpi AChE activity, Japanese encephalitis virus (JEV) titer and histopathological changes were studied in the frontal cortex, thalamus, midbrain, cerebellum, and hippocampus. There was significant impairment in memory and learning on 10 dpi which started improving from 33 dpi to 48 dpi by active avoidance test. Passive avoidance test showed decrease in transfer latency time of retention trial compared to acquisition on first, second, and third retention day trial compared to controls. AChE inhibition was more marked in the hippocampus, frontal cortex, and cerebellum on 10 dpi. However, AChE activity started improving from 33 dpi to 48 dpi. AChE activity in the thalamus and midbrain correlated with active avoidance test on 10 dpi and 33 dpi. Histopathological studies also revealed improvement on 33 and 48 compared to 10 dpi. The present study demonstrates transient memory and learning impairment which was associated with reduction in AChE, JEV titer, and damage in different brain regions of JEV infected rats.


Subject(s)
Acetylcholinesterase/metabolism , Encephalitis Virus, Japanese/physiology , Encephalitis, Japanese/enzymology , Encephalitis, Japanese/physiopathology , Memory , Animals , Avoidance Learning , Brain/enzymology , Brain/pathology , Brain/physiopathology , Brain/virology , Encephalitis, Japanese/pathology , Encephalitis, Japanese/virology , Rats, Wistar
13.
Sci Rep ; 6: 28142, 2016 06 23.
Article in English | MEDLINE | ID: mdl-27334554

ABSTRACT

The plethora of literature has supported the potential benefits of Resveratrol (RV) as a life-extending as well as an anticancer compound. However, these two functional discrepancies resulted at different concentration ranges. Likewise, the role of Resveratrol on adult neurogenesis still remains controversial and less understood despite its well documented health benefits. To gather insight into the biological effects of RV on neurogenesis, we evaluated the possible effects of the compound on the proliferation and survival of neural progenitor cells (NPCs) in culture, and in the hippocampus of aged rats. Resveratrol exerted biphasic effects on NPCs; low concentrations (10 µM) stimulated cell proliferation mediated by increased phosphorylation of extracellular signal-regulated kinases (ERKs) and p38 kinases, whereas high concentrations (>20 µM) exhibited inhibitory effects. Administration of Resveratrol (20 mg/kg body weight) to adult rats significantly increased the number of newly generated cells in the hippocampus, with upregulation of p-CREB and SIRT1 proteins implicated in neuronal survival and lifespan extension respectively. We have successfully demonstrated that Resveratrol exhibits dose dependent discrepancies and at a lower concentration can have a positive impact on the proliferation, survival of NPCs and aged rat hippocampal neurogenesis implicating its potential as a candidate for restorative therapies against age related disorders.


Subject(s)
Aging/drug effects , Neural Stem Cells/cytology , Neurogenesis/drug effects , Stilbenes/administration & dosage , A549 Cells , Aging/metabolism , Animals , Cell Proliferation/drug effects , Cell Survival/drug effects , Cells, Cultured , Cyclic AMP Response Element-Binding Protein/metabolism , Dose-Response Relationship, Drug , Extracellular Signal-Regulated MAP Kinases/metabolism , Hippocampus/drug effects , Hippocampus/metabolism , Humans , Neural Stem Cells/drug effects , Neural Stem Cells/metabolism , Phosphorylation/drug effects , Rats , Resveratrol , Sirtuin 1/metabolism , Stilbenes/pharmacology
14.
Physiol Behav ; 156: 148-55, 2016 Mar 15.
Article in English | MEDLINE | ID: mdl-26792528

ABSTRACT

Cognitive changes have been known in encephalitis but in Japanese encephalitis (JE) such studies are limited. This study aims at evaluating the spatial memory and learning and correlate with markers of cholinergic activity in the brain.12day old Wistar rats were inoculated with dose of 3×10(6)pfu/ml of JE virus. On 10, 33 and 48days post-inoculation (dpi), spatial memory and learning was assessed by Y maze. Brain biopsies from frontal cortex, corpus striatum, hippocampus and cerebellum were taken. Muscarinic cholinergic receptor was assayed by Quinuclidinyl benzylate (H3-QNB) binding, CHRM2 gene expression by real time PCR and choline acetyl transferase (ChAT) by Western blot. Spatial learning and memory showed significant decline in rats inoculated with JEV on 10 and 33dpi (47.5%, p<0.01; 30.2%, p<0.01). It started recovering on 48dpi. Muscarinic cholinergic receptors showed significant decrease in frontal cortex (31%, p=0.001; 26%, p=0.003), hippocampus (57%, p=0.001; 39.9%, p=0.002) and cerebellum (31.2%, p=0.008; 21.6%, p=0.007) but not in corpus striatum as compared to control. The mRNA expression of CHRM2 receptor gene showed significant decrease in the expression in frontal cortex (48%, p<0.001; 38%, p<0.01), hippocampus (43%, p<0.001; 37%, p<0.05) and cerebellum (46%, p<0.001; 42%, p<0.05) on 10 and 33dpi. ChAT showed significant fold decrease in the expression in frontal cortex (2.11, p<0.01, 1.12, p<0.05) and hippocampus (2.2, p<0.01, 1.41, p<0.05) on 10 and 33dpi. Correlation between ChAT, CHRM2 and total muscarinic receptor activity with spatial memory were found at different dpi. There was transient spatial learning and memory impairment which was associated with reduction of total muscarinic receptor binding, CHRM2 gene and ChAT expression in different brain region of rat infected with JE Virus.


Subject(s)
Acetylcholine/metabolism , Brain/metabolism , Choline O-Acetyltransferase/metabolism , Encephalitis, Japanese/psychology , Memory/physiology , Spatial Learning/physiology , Animals , Disease Models, Animal , Encephalitis Viruses, Japanese/isolation & purification , Encephalitis, Japanese/genetics , Encephalitis, Japanese/metabolism , Hippocampus/metabolism , Male , Rats , Rats, Wistar , Receptors, Muscarinic/metabolism
15.
Mol Neurobiol ; 53(6): 3670-3689, 2016 08.
Article in English | MEDLINE | ID: mdl-26115703

ABSTRACT

Oral administration of low doses of cypermethrin to pregnant Wistar rats led to a dose-dependent differences in the induction of xenobiotic-metabolizing cytochrome P450s (CYPs) messenger RNA (mRNA) and protein in brain regions isolated from the offsprings postnatally at 3 weeks that persisted up to adulthood. Similar alterations were observed in the expression of rate-limiting enzymes of neurotransmitter synthesis in brain regions of rat offsprings. These persistent changes were associated with alterations in circulating levels of growth hormone (GH), cognitive functions, and accumulation of cypermethrin and its metabolites in brain regions of exposed offsprings. Though molecular docking studies failed to identify similarities between the docked conformations of cypermethrin with CYPs and neurotransmitter receptors, in silico analysis identified regulatory sequences of CYPs in the promoter region of rate-limiting enzymes of neurotransmitter synthesis. Further, rechallenge of the prenatally exposed offsprings at adulthood with cypermethrin (p.o. 10 mg/kg × 6 days) led to a greater magnitude of alterations in the expression of CYPs and rate-limiting enzymes of neurotransmitter synthesis in different brain regions. These alterations were associated with a greater magnitude of decrease in the circulating levels of GH and cognitive functions in rechallenged offsprings. Our data has led us to suggest that due to the immaturity of CYPs in fetus or during early development, even the low-level exposure of cypermethrin may be sufficient to interact with the CYPs, which in turn affect the neurotransmission processes and may help in explaining the developmental neurotoxicity of cypermethrin.


Subject(s)
Brain/pathology , Cytochrome P-450 Enzyme System/metabolism , Neurotransmitter Agents/biosynthesis , Prenatal Exposure Delayed Effects/enzymology , Prenatal Exposure Delayed Effects/pathology , Pyrethrins/adverse effects , Xenobiotics/metabolism , Animals , Animals, Newborn , Biocatalysis , Brain/enzymology , Computer Simulation , Female , Gene Expression Regulation , Intercellular Signaling Peptides and Proteins/blood , Learning/drug effects , Male , Metabolome/genetics , Molecular Docking Simulation , Pregnancy , Prenatal Exposure Delayed Effects/blood , Prenatal Exposure Delayed Effects/genetics , Pyrethrins/chemistry , Pyrethrins/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , Rats, Wistar , Sequence Analysis, DNA , Spatial Memory/drug effects , Structural Homology, Protein
16.
Sci Rep ; 5: 14038, 2015 Sep 15.
Article in English | MEDLINE | ID: mdl-26370177

ABSTRACT

We demonstrate the role of molecular switching of TrkA/p75(NTR) signaling cascade in organophosphate pesticide-Monocrotophos (MCP) induced neurotoxicity in stem cell derived cholinergic neurons and in rat brain. Our in-silico studies reveal that MCP followed the similar pattern of binding as staurosporine and AG-879 (known inhibitors of TrkA) with TrkA protein (PDB ID: 4AOJ) at the ATP binding sites. This binding of MCP to TrkA led to the conformational change in this protein and triggers the cell death cascades. The in-silico findings are validated by observing the down regulated levels of phosphorylated TrkA and its downstream molecules viz., pERK1/2, pAkt and pCREB in MCP-exposed cells. We observe that these MCP induced alterations in pTrkA and downstream signaling molecules are found to be associated with apoptosis and injury to neurons. The down-regulation of TrkA could be linked to increased p75(NTR). The in-vitro studies could be correlated in the rat model. The switching of TrkA/p75(NTR) signaling plays a central role in MCP-induced neural injury in rBNSCs and behavioral changes in exposed rats. Our studies significantly advance the understanding of the switching of TrkA/p75(NTR) that may pave the way for the application of TrkA inducer/p75(NTR) inhibitor for potential therapeutic intervention in various neurodegenerative disorders.


Subject(s)
Cholinesterase Inhibitors/pharmacology , Insecticides/pharmacology , Monocrotophos/pharmacology , Receptor, trkA/metabolism , Receptors, Nerve Growth Factor/metabolism , Signal Transduction/drug effects , Animals , Apoptosis/drug effects , Behavior, Animal/drug effects , Brain/drug effects , Brain/metabolism , Cell Differentiation/drug effects , Cells, Cultured , Cholinesterase Inhibitors/chemistry , Cholinesterase Inhibitors/toxicity , Insecticides/chemistry , Insecticides/toxicity , Models, Molecular , Molecular Conformation , Molecular Docking Simulation , Monocrotophos/chemistry , Monocrotophos/toxicity , Nerve Tissue Proteins , Neural Stem Cells/cytology , Neural Stem Cells/drug effects , Neural Stem Cells/metabolism , Neurons/cytology , Neurons/drug effects , Neurons/metabolism , Rats , Receptor, trkA/antagonists & inhibitors , Receptor, trkA/chemistry , Receptors, Growth Factor , Structure-Activity Relationship
17.
ACS Nano ; 9(5): 4850-71, 2015 May 26.
Article in English | MEDLINE | ID: mdl-25825926

ABSTRACT

Sustained and safe delivery of dopamine across the blood brain barrier (BBB) is a major hurdle for successful therapy in Parkinson's disease (PD), a neurodegenerative disorder. Therefore, in the present study we designed neurotransmitter dopamine-loaded PLGA nanoparticles (DA NPs) to deliver dopamine to the brain. These nanoparticles slowly and constantly released dopamine, showed reduced clearance of dopamine in plasma, reduced quinone adduct formation, and decreased dopamine autoxidation. DA NPs were internalized in dopaminergic SH-SY5Y cells and dopaminergic neurons in the substantia nigra and striatum, regions affected in PD. Treatment with DA NPs did not cause reduction in cell viability and morphological deterioration in SH-SY5Y, as compared to bulk dopamine-treated cells, which showed reduced viability. Herein, we report that these NPs were able to cross the BBB and capillary endothelium in the striatum and substantia nigra in a 6-hydroxydopamine (6-OHDA)-induced rat model of PD. Systemic intravenous administration of DA NPs caused significantly increased levels of dopamine and its metabolites and reduced dopamine-D2 receptor supersensitivity in the striatum of parkinsonian rats. Further, DA NPs significantly recovered neurobehavioral abnormalities in 6-OHDA-induced parkinsonian rats. Dopamine delivered through NPs did not cause additional generation of ROS, dopaminergic neuron degeneration, and ultrastructural changes in the striatum and substantia nigra as compared to 6-OHDA-lesioned rats. Interestingly, dopamine delivery through nanoformulation neither caused alterations in the heart rate and blood pressure nor showed any abrupt pathological change in the brain and other peripheral organs. These results suggest that NPs delivered dopamine into the brain, reduced dopamine autoxidation-mediated toxicity, and ultimately reversed neurochemical and neurobehavioral deficits in parkinsonian rats.


Subject(s)
Blood-Brain Barrier/metabolism , Dopamine/chemistry , Dopamine/metabolism , Nanoparticles/chemistry , Parkinson Disease/drug therapy , Parkinson Disease/physiopathology , Animals , Cell Line, Tumor , Dopamine/adverse effects , Dopaminergic Neurons/metabolism , Drug Carriers/adverse effects , Drug Carriers/chemistry , Drug Carriers/metabolism , Drug Liberation , Humans , Lactic Acid/chemistry , Neostriatum/drug effects , Neostriatum/metabolism , Oxidation-Reduction , Oxidopamine/chemistry , Oxidopamine/pharmacology , Oxidopamine/therapeutic use , Parkinson Disease/metabolism , Polyglycolic Acid/chemistry , Polylactic Acid-Polyglycolic Acid Copolymer , Rats , Rats, Wistar , Receptors, Dopamine/metabolism , Safety , Up-Regulation/drug effects
18.
Article in English | MEDLINE | ID: mdl-24321757

ABSTRACT

A novel analytical approach based on molecularly imprinted solid phase extraction (MISPE) coupled with dispersive liquid-liquid microextraction (DLLME), and injector port silylation (IPS) has been developed for the selective preconcentration, derivatization and analysis of 3-phenoxybenzoic acid (3-PBA) using gas chromatography-tandem mass spectrometry (GC-MS/MS) in complex biological samples such as rat blood and liver. Factors affecting the synthesis of MIP were evaluated and the best monomer and cross-linker were selected based on binding affinity studies. Various parameters of MISPE, DLLME and IPS were optimized for the selective preconcentration and derivatization of 3-PBA. The developed method offers a good linearity over the calibration range of 0.02-2.5ngmg(-1) and 7.5-2000ngmL(-1) for liver and blood respectively. Under optimized conditions, the recovery of 3-PBA in liver and blood samples were found to be in the range of 83-91%. The detection limit was found to be 0.0045ngmg(-1) and 1.82ngmL(-1) in liver and blood respectively. SRM transition of 271→227 and 271→197 has been selected as quantifier and qualifier transition for 3-PBA derivative. Intra and inter-day precision for five replicates in a day and for five, successive days was found to be less than 8%. The method developed was successfully applied to real samples, i.e. rat blood and tissue for quantitative evaluation of 3-PBA. The analytical approach developed is rapid, economic, simple, eco-friendly and possess immense utility for the analysis of analytes with polar functional groups in complex biological samples by GC-MS/MS.


Subject(s)
Benzoates/analysis , Benzoates/blood , Gas Chromatography-Mass Spectrometry/methods , Liquid Phase Microextraction/methods , Liver/chemistry , Molecular Imprinting , Animals , Gas Chromatography-Mass Spectrometry/economics , Limit of Detection , Liquid Phase Microextraction/economics , Rats , Rats, Wistar , Tandem Mass Spectrometry/economics , Tandem Mass Spectrometry/methods
19.
J Neurol Sci ; 329(1-2): 11-6, 2013 Jun 15.
Article in English | MEDLINE | ID: mdl-23562297

ABSTRACT

BACKGROUND: Vitamin B12 deficiency is a well recognized cause of posterolateral myelopathy. In Indian subcontinent, it may coexist with nutritional copper deficiency producing partial response of patients to B12 supplementation. Hence the study was planned to look for association of hypocupremia and B12 deficiency. METHODS: Twenty-three patients with posterolateral myelopathy (Romberg sign positive) were enrolled and investigated for levels of vitamin B12, copper and zinc and followed up for six months. RESULT: In three patients, copper deficiency alone was found to be the cause. In another three, both copper and vitamin B12 were deficient. In all these six patients, ceruloplasmin and 24h urinary copper were found to be low suggesting dietary copper deficiency. Hyperzincemia was found in four of these patients. Magnetic resonance imaging of spine was normal in lone Cu deficient patients but showed T2 hyperintensity of posterior column in lone B12 or combined B12 and copper deficiency. CONCLUSION: In cases of B12 deficiency myelopathy not responding to supplementation, copper deficiency must be sought at the earliest to avoid and treat persistent neurological disability.


Subject(s)
Ataxia/complications , Copper/blood , Spinal Cord Diseases/blood , Spinal Cord Diseases/complications , Vitamin B 12/blood , Zinc/blood , Action Potentials/physiology , Adult , Analysis of Variance , Ataxia/blood , Brain/pathology , Disability Evaluation , Female , Follow-Up Studies , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Spinal Cord/pathology , Statistics, Nonparametric , Vitamin B 12 Deficiency/complications
20.
Fitoterapia ; 83(6): 1092-9, 2012 Sep.
Article in English | MEDLINE | ID: mdl-22579842

ABSTRACT

This study was undertaken to ascertain the antipsychotic properties of Rauwolfia tetraphylla L. leaves and to isolate and characterize the antipsychotic constituents. Among the MeOH extract and some alkaloidal fractions at different pHs, the alkaloidal CHCl(3) fraction at pH-9 (2C) showed the highest antipsychotic activity against dopaminergic (DA-D(2)) and serotonergic (5-HT(2A)) receptors in-vitro and amphetamine induced hyperactive mouse model in-vivo. The activity guided isolation of CHCl(3) fraction (2C) afforded six indole alkaloids: 10-methoxytetrahydroalstonine (1), isoreserpiline (2), an isomeric mixture of 11-demethoxyreserpiline (3) and 10-demethoxyreserpiline (4), α-yohimbine (5) and reserpiline (6). Given orally, alkaloids 3-6 showed significant antipsychotic activity in a dose dependent manner. None of the extract, alkaloidal fractions or alkaloids showed any extra pyramidal symptoms at the tested doses. It was also observed that MeOH extract was behaving similar to other clinically used novel atypical antipsychotics in having 5-HT(2A) occupancy greater than the DA-D(2) receptor at the tested doses. Further toxicity and safety evaluation studies of MeOH extracts of R. tetraphylla leaves at different doses (10, 100, 300 and 2000 mg/kg) on female Swiss albino mice showed that MeOH extract is non toxic. The isolated alkaloids, 3-6 could serve as a promising lead structure for drug development of treating psychotic conditions in human.


Subject(s)
Antipsychotic Agents/therapeutic use , Hyperkinesis/drug therapy , Indole Alkaloids/therapeutic use , Phytotherapy , Plant Extracts/therapeutic use , Rauwolfia/chemistry , Receptors, Biogenic Amine/metabolism , Amphetamine , Animals , Antipsychotic Agents/isolation & purification , Antipsychotic Agents/pharmacology , Dose-Response Relationship, Drug , Female , Hydrogen-Ion Concentration , Hyperkinesis/chemically induced , Hyperkinesis/metabolism , Indole Alkaloids/chemistry , Indole Alkaloids/pharmacology , Mice , Mice, Inbred Strains , Neurotransmitter Agents/isolation & purification , Neurotransmitter Agents/pharmacology , Neurotransmitter Agents/therapeutic use , Plant Extracts/chemistry , Plant Extracts/pharmacology , Plant Leaves/chemistry , Receptors, Dopamine/metabolism , Receptors, Serotonin/metabolism
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